Yike! Don’t tell her to start Wolfeing with THE DOORBELL RANG! You need a solid backgrounding in the Canon to properly appreciate THE DOORBELL RANG. Besides, it’s 1965 in THE DOORBELL RANG and that means that Archie doesn’t wear hats.
C’mere, Icerigger honey…don’t be taking no mystery-reading tips from a guy who read TIGER IN THE SMOKE and didn’t notice that Campion was in it…what YOU want is a nice copy of Rex Stout’s THE LEAGUE OF FRIGHTENED MEN (1935) or TOO MANY COOKS (1938)…two of his best Nero Wolfe novels, and with Thirties atmosphere to boot.
One the same note, I’d suggest CLOUDS OF WITNESS (1926) as the best introduction to Sayers. It’s deftly plotted and gives you Lord Peter as his most Bertie-Woosterish (except that he makes a daredevil flight in an aeroplane). THE NINE TAILORS is a Great Book, but it can be sluggish going if you’re not already fond of the big poofter.
I made the mistake of reading CURTAIN as my introduction to Agatha Christie. Don’t do that. It’s a great book, and I don’t want to give away an important facet of it, but my wife won’t read it because she’s afraid it will spoil all the other Poirot books for her.
I believe the title given by a previous poster as BEYOND ZERO is actually TOWARD ZERO. It’s a very good book. ORIENT EXPRESS is a classic; Poirot at his best. There’s another one called, IIRC, ELEPHANTS CAN REMEMBER. Also very good, and a psychological mystery, if that’s your cuppa tea. POCKETFUL OF RYE is also enjoyable. I like Miss Marple. Don’t care much for Tommy and Tuppence, but my wife likes them. There are also some short story collections featuring Poirot, such as THE 12 LABORS OF HERCULES. They are cracking for a short, enjoyable read on a rainy Saturday night, if, like me, you have no social life.
I second the poster who recommended Sherlock Holmes, especially the short stories. I’m fortunate enough to have the complete Sherlock Holmes in a two-volume set, and the short stories are just the thing when I’m prowling around for a new read between novels.
Happy reading! I’m sure you’ll enjoy Dame Agatha. Just don’t read CURTAIN until you’re good and ready.